Commentary

When the Plurality criterion requires that B not be elected, it means that even if all the voters who gave B some ranking were to elevate him to the top position, he would still not be the First Preference Plurality winner.

It also means that A has a stronger pairwise victory over B than B has even a path of victories to any other candidate.

It is conceivable that if B were elected, voters might not consider this a legitimate result.